Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
  • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
  • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
  • H04L1/1867—Arrangements specially adapted for the transmitter end
  • H04L1/1874—Buffer management
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
  • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
  • H04L1/1607—Details of the supervisory signal
  • H04L1/1628—List acknowledgements, i.e. the acknowledgement message consisting of a list of identifiers, e.g. of sequence numbers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W28/00—Network traffic management; Network resource management
  • H04W28/02—Traffic management, e.g. flow control or congestion control
  • H04W28/0205—Traffic management, e.g. flow control or congestion control at the air interface
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/20—Control channels or signalling for resource management
  • H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
  • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
  • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
  • H04L1/1829—Arrangements specially adapted for the receiver end
  • H04L1/1835—Buffer management

Definitions

• TITLE Communication methods between a terminal and a base station, terminal, base station and corresponding computer program.
• the field of the invention is that of telecommunications.
• the invention relates to communications between a terminal and a base station, especially in unlicensed frequency bands.
• the invention finds in particular, and not exclusively, applications in the field of 5G (in English NR for “New Radio”), for communications on unlicensed frequency bands (in English “NR-U” for “NR -based access to unlicensed spectrum ”).
• access protocols In order to facilitate access to a channel in an unlicensed frequency band, access protocols have been proposed, such as the LBT access protocol (in English “Listen Before Talk”, in French “listen before talk” ), and in particular its so-called “category 4” version.
• a device when a device wishes to transmit a signal in a channel belonging to an unlicensed frequency band, it first listens to the channel for a predetermined period (for example 34 ps). If the channel is busy, the sending equipment continues to listen to the channel, until the channel is detected as unoccupied or inactive ("idle").
• a predetermined period for example 34 ps.
• determining the occupation of a channel is based on an energy measurement.
• the transmitting equipment estimates the energy received on this channel and the compares to a predefined threshold. If the received energy exceeds this threshold, the channel is considered busy. Otherwise, it is considered unoccupied.
• the transmitting equipment checks that the channel remains inactive for a predetermined time (eg 34 ps). Once this time has elapsed, the transmitting equipment draws a random value (in English "backoff") from a predefined range (for example an integer between 5 and 15), and checks for each counter value whether the channel remains unoccupied. , counting down from the value drawn.
• a predefined range for example an integer between 5 and 15
• each counter value is associated with a 9 ps step. Thus, if the channel remains unoccupied for a period of 9 ps, the counter value is decremented by 1.
• the sending equipment If during the countdown the channel is again occupied (in English "busy"), the sending equipment retains the current value of the counter and continues listening to the channel, until it detects that the channel is free again. The sending equipment checks again that the channel remains unoccupied for a predetermined time (eg 34 ps), then resumes counting from the last counter value.
• a predetermined time eg 34 ps
• the sending equipment can start transmitting data.
• the transmission time is called COT (in English “Channel Occupancy Time”, in French “canal occupation time”).
• communications can therefore be delayed while the channel is busy.
• LTE Physical layer procedures for shared spectrum channel access (3GPP TS 37.213 version 15.0.0 Release 15)
• a base station when a base station wishes to transmit data to user equipment, it notably transmits data on the PDSCH channel (“ Physical Downlink Shared Channel ”) and control information (DCI for“ Downlink Control Information ”).
• PDSCH Physical Downlink Shared Channel
• DCI Downlink Control Information
• the control information carries information relating to the reception of data, such as the time / frequency resource or the coding and modulation scheme. used to transmit the data.
• Such control information can also carry information relating to the time / frequency resource to be used by the user equipment to indicate whether the data has been decoded, also called the time / frequency resource for the “feedback”.
• the user equipment sends an ACK type message to the resource for feedback if the data packet is correctly decoded, or a NACK type message otherwise.
• the base station Since the base station allocates the time / frequency resource to be used by the UE for feedback, the base station can read the message it receives on this resource to verify if the UE has decoded the data.
• the base station If the base station receives an ACK type message associated with a current data packet, it can consider that the current data packet has been correctly received.
• the base station If the base station receives a NACK type message associated with a current data packet, it can retransmit the current data packet, possibly with different redundancy data (RV or “Redundancy values”). In this way, the UE can reconstruct the current data packet using the initial transmission and re-transmission.
• RV redundancy data
• the base station if the base station does not receive any message on the time / frequency resource allocated for the feedback, the base station considers that the communication has been interrupted (DTX for “Discontinuous transmission”). The base station assumes that the UE has not received the DCI control information, therefore has not been aware of the transmission of a data packet and has not attempted to decode it. The base station then decides to transmit the DCI control information again with a different coding, as well as to retransmit the data packet on the PDSCH channel, possibly with a different modulation and coding scheme.
• transmission by the user equipment of a message to indicate whether the data packet has been decoded can be delayed as long as the channel is busy.
• user equipment may have decoded a data packet, and wish to transmit an ACK type message on the resource allocated for feedback.
• the user equipment runs the LBT access protocol. As long as the channel is busy, transmission of the ACK message is prohibited.
• the base station not receiving any message on the time / frequency resource allocated for feedback, will consider that the communication has been interrupted (DTX). The base station will transmit the DCI control information and the data packet again, resulting in loss of spectral efficiency.
• the invention provides, according to one embodiment, a method of managing a communication between a base station and a terminal.
• a method of managing a communication between a base station and a terminal is implemented at the level of a terminal.
• the terminal is associated with at least one memory comprising at least two storage areas, and implements:
• the representative state of a transmission belongs to the group comprising:
• the data packet has been decoded (for example of ACK type);
• the data packet has not been decoded (for example of NACK type);
• control information has not been received (eg DTX type).
• the proposed solution thus makes it possible to keep in memory the states representative of the transmissions of data packets from the base station to the terminal, as long as the terminal is not authorized to transmit.
• the proposed solution makes it possible to improve the “HARQ-ACK feedback” technique.
• the terminal When the terminal is authorized to transmit, for example when the channel is considered unoccupied following the progress of the LBT access protocol, the terminal transmits to the base station the history of states representative of the transmissions. In this way, the base station receives information about previous transmissions, and can decide whether it is desirable to retransmit certain data packets (especially data packets associated with a NACK or DTX state).
• the base station can determine, during a following transmission:
• the terminal has not actually received the control information for the current transmission (and return the control information with possibly a suitable coding rate and the current data packet with a suitable coding and modulation scheme), or
• the proposed solution is well suited to communications on unlicensed frequency bands (NR-U).
• the method also implements at least one step of storing, in one of the storage areas, a state representative of a transmission, by the base station, of at least one packet of data. previous data and control information associated with the previous data packet, referred to as the previous transmission, said storage area being identified from the storage area indicator carried by the control information associated with the current data packet.
• the storage of a state representative of a current transmission can be used to determine the state representative of a previous transmission.
• the storage areas of a memory are organized in a stack, and the method implements:
• the method implements: the detection, in the control information associated with the current data packet, of a reception indicator indicating that the base station has received all of the states representative of previous transmissions, stored in storage areas;
• a new indicator is proposed, denoted for example NAI (“New Ack Indication”), making it possible to inform the terminal that the base station has received all of the states representative of the previous transmissions and that it It is therefore possible to delete these states from the storage areas.
• NAI New Ack Indication
• the terminal is associated with at least two memories.
• the storage area can be identified by a storage area indicator (denoted for example SetlD) and by a memory indicator (denoted for example AckJD).
• the different memories can have a different number of storage areas.
• each memory can be associated with a different level of quality of service.
• the invention in another embodiment, relates to a terminal capable of communicating with a base station, comprising at least one memory comprising at least two storage areas, and at least one processing unit configured for: - store, in one of the storage areas, at least one state representative of a transmission, by the base station, of at least one current data packet and control information associated with the current data packet, called transmission current, said storage area being identified by a storage area indicator carried by the control information associated with the current data packet,
• the processing unit is configured to store states representative of successive transmissions, and to transmit all of these states when the terminal is authorized to transmit.
• the processing unit is a processor operably coupled to the memory or memories associated with the terminal.
• Such a terminal is particularly suitable for implementing the method of managing a communication described above.
• This is, for example, user equipment such as a cell phone.
• This terminal could of course include the various characteristics relating to the method according to the invention, which can be combined or taken in isolation. Thus, the characteristics and advantages of this terminal are the same as those of the method described above. Therefore, they are not detailed further.
• the invention also relates, according to one embodiment, to a method of communication between a base station and a terminal.
• a method of communication between a base station and a terminal is implemented at the level of a base station.
• the terminal being associated with at least one memory comprising at least two storage areas
• the base station implements:
• the control information bearing a storage area indicator identifying a storage area a state representative of the current transmission, among the storage areas,
• the base station knows, for each transmission, in which storage area the state of the transmission can be stored.
• the proposed solution thus makes it possible to keep in memory the states representative of the transmissions of data packets from the base station to the terminal, as long as the terminal is not authorized to transmit.
• the base station receives the states representative of previous transmissions, and can decide whether it is desirable to retransmit certain data packets.
• control information also carries at least one piece of information belonging to the group comprising:
• a memory indicator (denoted for example AckJD) identifying a memory from among said at least one memory associated with the terminal;
• a reception indicator (denoted for example NAI) indicating that the base station has received all of the stored states representative of the transmissions;
• the reception indicator changes state upon receipt of all the states representative of transmissions, and is transmitted in the control information of a subsequent transmission.
• the terminal can detect that the base station has received the states representative of the previous transmissions, and refresh the memory or memories associated with it.
• the memory is organized in a stack, and the control information associated with the first data packet carries a storage area indicator identifying the storage area corresponding to the first level of the stack, and the control information associated with the following data packets respectively bear a storage area indicator identifying the storage area corresponding to the directly higher level.
• the method implements:
• the method implements a retransmission of the 'set of data packets and control information associated with these data packets.
• the invention relates to a base station capable of communicating with a terminal associated with at least one memory comprising at least two storage areas, said base station comprising at least one processing unit configured for:
• control information bearing a storage area indicator identifying a storage area of a state representative of the transmission current, among the storage areas,
• the processing unit is configured to transmit data packets and control information, and to receive all of the states representative of the transmissions when the terminal is authorized to transmit.
• the processing unit is a processor operably coupled to a memory of the base station.
• Such a base station is particularly suitable for implementing the communication method described above.
• This is for example an eNodeB.
• the base station could of course include the various characteristics relating to the method according to the invention, which can be combined or taken in isolation. Thus, the characteristics and advantages of the base station are the same as those of the method described above. Therefore, they are not detailed further.
• the invention also relates to one or more computer programs comprising instructions for the implementation of at least one method as described above. when this or these programs are executed by at least one processor.
• the invention also relates to an information medium readable by a computer, and comprising instructions of a computer program as mentioned above.
• Figure 1 illustrates the main steps implemented by a base station according to one embodiment of the invention
• FIG 2 illustrates the main steps implemented by a terminal according to one embodiment of the invention
• FIG 3 illustrates the structure of different memories associated with a terminal according to one embodiment of the invention
• FIGs 4A to 4D illustrate a first example of communication between a base station and a terminal according to an embodiment of the invention
• FIGS. 5A to 5E illustrate a second example of communication between a base station and a terminal according to an embodiment of the invention
• FIGs 6A to 6D illustrate a third example of communication between a base station and a terminal according to an embodiment of the invention
• FIG 7 shows the simplified structure of a terminal implementing a communication management method according to one embodiment of the invention
• FIG. 8 presents the simplified structure of a base station implementing a communication method according to an embodiment of the invention. 5. Description of an embodiment of the invention
• the general principle of the invention is based on the transmission of data packets and control information associated with these data packets in downlink, ie from a base station to a terminal, and storage in storage areas.
• the terminal transmits to the base station all the states representative of the transmissions, when it is authorized to transmit.
• the base station upon receipt of all the states representative of the transmissions, the base station can determine whether there has indeed been one or more transmission failures, in which case it is necessary to retransmit the corresponding data packet and the corresponding data packet. associated control information.
• the base station does not assume that communication has been interrupted in the absence of a message on a time / frequency resource allocated for feedback.
• the base station determines that the communication has been terminated only upon receipt of a state representative of the transmission such as transmission failure, such as DTX.
• the terminal transmits to the base station all the states stored in the storage areas when it is authorized to transmit on a time / frequency resource identified from the control information, the control information.
• control carrying information relating to at least one time / frequency resource intended to be used by the terminal to transmit to the base station all the states representative of the transmissions.
• this information relating to at least one time / frequency resource for the feedback can be common to the control information associated with different data packets.
• the control information associated with different data packets identifies one (or more) same time / frequency resource to be used by the terminal for feedback.
• the communication network is a cellular network.
• FIGS. 1 and 2 the main steps implemented by a terminal and a base station of the communication network according to one embodiment of the invention are presented.
• the terminal is associated with at least one memory.
• a memory can therefore be an internal component of the terminal, or an external component belonging to another item of equipment in communication with the terminal, such as a remote server.
• the address of such a memory can in particular be defined by a memory indicator, denoted for example AckJD.
• Such a memory comprises at least two storage areas. The address of each storage area can be defined by a storage area indicator, denoted for example SetlD.
• the memory is a stack memory, and each storage area corresponds to a segment of the stack.
• the base station implements at least one step 11 of transmitting at least one data packet and control information associated with the data packet.
• Current transmission is the transmission of a current data packet from the base station to the terminal, for example on a PDSCH type channel, and of control information associated with the current data packet, for example of DCI type.
• Several transmission steps can be implemented to successively transmit the various data packets and associated control information.
• control information carries a storage area indicator identifying a storage area of a state representative of the current transmission, among the storage areas of the memory associated with the terminal.
• a different storage area can be allocated by the base station.
• the terminal implements, for its part, at least one step 21 of storing a state representative of a current transmission, ie of the transmission by the base station of at least one packet of current data (for example on a PDSCH type channel) and control information (for example of DCI type) associated with the current data packet.
• the storage area is identified by the storage area indicator carried by the control information associated with the current data packet. It is noted that, in certain cases, the reception of a current data packet and associated control information makes it possible to store, in one of the storage areas, a state representative of a previous transmission.
• the terminal When the terminal is authorized to transmit, it implements a transmission 22, to the base station, of all the states S stored in the storage areas of at least one memory.
• the base station for its part, implements a step of receiving 12 of all the states S representative of the transmissions.
• the terminal is associated with one or more memories, identified by a memory indicator AckJD.
• AckJD memory indicator
• Each memory is divided into several segments, corresponding to different storage areas.
• Each storage area is identified by a SetJD storage area indicator. The number of storage areas in each memory may be different.
• the AckJD memory can be considered as a buffer memory making it possible to store the representative state of transmissions with an identifier (for example ACK if the data packet has been decoded, NACK if the data packet has not been decoded, or DTX if control information has not been received).
• the storage area indicator can be thought of as a pointer to the buffer.
• a reception indicator N Al is introduced, indicating that the base station has received all of the stored states representative of previous transmissions.
• control information for example of DCI type
• a corresponding data packet for example on the PDSCH channel
• the control information carries the storage area indicator and possibly the memory indicators. and / or reception.
• the control information also makes it possible to identify one or more time / frequency resource for the feedback, intended to be used (s) by the terminal to transmit to the base station all the data.
• representative states of transmissions For example, the reception indicator NAI is a binary value (0 or 1) which indicates whether all of the states representative of the transmissions, stored in the memory AckJD, have been received by the base station. For a current transmission, identifying an AckJD memory, if the value of the reception indicator is modified compared to the previous transmission identifying the same AckJD memory, this means that the base station has received all the states representative of the transmissions, stored in AckJD memory. Otherwise, it means that the base station has not yet received the representative states, stored in the memory AckJD.
• the terminal is not authorized to send (failure of the LBT access protocol for example). It cannot therefore transmit its status (“ACK”) - for example on the time / frequency resource allocated for feedback.
• ACK the status
• the base station schedules the transmission of a second data packet on the PDSCH channel and the associated DCI control information, called the second transmission.
• control associated with the following data packets respectively bear a storage area indicator identifying the storage area corresponding to the directly higher level.
• the terminal does not receive the DCI control information, it does not know that a second data packet has been transmitted. It therefore does not store any information in the AckJD memory.
• the base station does not receive any information on the time / frequency resource allocated for feedback.
• the base station schedules the transmission of a third data packet on the PDSCH channel and associated DCI control information, called a third transmission.
• the terminal can detect that at least one storage area of a lower level than the current storage area of the third data packet is empty, which means that the information of checks of a previous transmission (ie the second transmission) were not received.
• the terminal is finally authorized to transmit, for example following the successful execution of the LBT access protocol.
• the value of the indicator N Al goes from 0 to 1, and the base station programs it.
• the reception indicator therefore changes state on reception of all representative states of transmissions, and may be transmitted in the control information of a subsequent transmission.
• FIGS. 5A to 5E a second example of communication between a base station and a terminal according to an embodiment of the invention is now presented.
• Figures 5A to 5C are identical to Figures 4A to 4C and are therefore not described in more detail.
• the value of the NAI indicator goes from 0 to 1, and the base station programs the transmission.
• a fourth data packet on the PDSCH channel and associated DCI control information called a fourth transmission.
• the terminal does not receive the DCI control information.
• the terminal therefore does not know that a fourth data packet has been sent. It does not store any information in AckJD memory, and the base station does not receive any information about the time / frequency resource allocated for feedback.
• the base station schedules the transmission of a fifth data packet on the PDSCH channel and associated DCI control information, called a fifth transmission.
• the terminal can detect that at least one storage area of a lower level than the storage area of the fifth data packet is empty, which means that the control information of the previous transmission (ie the fourth transmission) were not received.
• the base station can therefore detect, from the control information of a current transmission, a transmission failure of a previous transmission (i.e. when the terminal does not receive the control information).
• the base station can retransmit the corresponding data packets and the associated control information, possibly by adapting the coding rate and / or the modulation scheme. and coding.
• the base station implements a retransmission of all the corresponding data packets and control information associated with these data packets. It is then possible to empty the memory.
• a single memory was associated with a terminal.
• several memories can be associated with a terminal.
• the different memories can be used for different services having different quality of service (QoS) levels.
• QoS quality of service
• the user of the terminal has subscribed to two different services: a first service of the download type, tolerating a certain latency, and a second service of the mobile telephone type, requiring low latency.
• the states representative of the transmissions associated with the first service and the second service, stored in the single memory are mixed.
• the base station which receives all the states can it is therefore difficult to control the quality of service and the spectral efficiency of these two services.
• the base station may decide not to wait to receive all of the states and assume, after a predetermined time, that all transmissions have failed (DTX).
• DTX transmissions have failed
• the base station could have waited longer to receive the states representative of the transmissions associated with the first service, before assuming that all the transmissions had failed. .
• the base station can wait longer for the reception of the states representative of the transmissions associated with the first service (supporting a higher latency), it does not systematically consider a failure of the transmissions associated with the first service, and therefore does not retransmit necessarily the data packets associated with this first service.
• the terminal is not authorized to transmit (failure of the LBT access protocol for example). It cannot therefore transmit its state (“ACK”) to the base station.
• ACK state
• the base station may decide not to wait to receive all the states and assume, after a predetermined time, that all transmissions associated with the second service have failed (DTX), and scheduling a re-transmission of the corresponding data packets.
• the value of the NAI indicator changes from 0 to 1, and the base station schedules the re-transmission of the first data packet associated with the second service and the associated DCI control information.
• the memory associated with the low latency service may have a size, i.e. a number of storage areas, smaller than that of the memory associated with the service tolerating a higher latency.
• the base station implements a retransmission of the set of corresponding data packets associated with the low latency service and associated control information.
• the last memory storage area is full, and the base station still has not received all of the representative transmission states, it means that the load is high, i.e. the channel is heavily occupied. In this case, the base station assumes that all previous transmissions, corresponding to states stored in memory, have failed (DTX).
• a memory comprising four or five storage areas can be used.
• the base station can identify, in the control information, several time / frequency resources for the feedback. For example, the base station can allocate two time / frequency resources for a current transmission so that the terminal can report the status of the transmission. The terminal can then run the LBT access protocol on a first resource. If successful, the terminal can transmit the transmission status to this first resource. If this fails, the terminal can roll out the LBT access protocol on the second resource. This optimizes the probability of success of the LBT access protocol.
• a terminal comprises at least one memory 71 comprising a buffer memory comprising at least two storage areas, at least one processing unit 72, equipped for example with a programmable computing machine or with a control machine. dedicated calculation, for example a processor P, and controlled by the computer program 73, implementing steps of the method for managing a communication according to at least one embodiment of the invention.
• the code instructions of the computer program 73 are for example loaded into a RAM memory before being executed by the processor of the processing unit 72.
• the processor of the processing unit 72 implements steps of the method of managing a communication described above, according to the instructions of the computer program 73, to:
• such a base station comprises at least one memory 81 comprising a buffer memory, at least one processing unit 82, equipped for example with a programmable computing machine or with a dedicated computing machine, for example. example a processor P, and controlled by the computer program 83, implementing steps of the communication method according to at least one embodiment of the invention.
• the code instructions of the computer program 83 are for example loaded into a RAM memory before being executed by the processor of the processing unit 82.
• the processor of the processing unit 82 implements steps of the communication method described above, according to the instructions of the computer program 83, to:
• control information bearing a storage area indicator identifying a storage area of a state representative of the current transmission, among the storage areas of a memory associated with the terminal,

Landscapes

• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=67660298

Family Applications (1)

Country Status (4)

Family Cites Families (7)

• 2019
  • 2019-04-26 FR FR1904462A patent/FR3095565A1/fr not_active Withdrawn
• 2020
  • 2020-04-20 WO PCT/EP2020/061010 patent/WO2020216720A1/fr unknown
  • 2020-04-20 US US17/606,346 patent/US20220231799A1/en active Pending
  • 2020-04-20 EP EP20719201.4A patent/EP3959920A1/de active Pending

Also Published As

Similar Documents

Legal Events